Switch-controlling mechanism.



E. W. HEDBERG.

SWITCH CONTROLLING MECHANISM.

APPLICATION FILED JUNE 29, I9I6.

1,258,679. Patented Mar. 12, 1918.

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dZUd/"d Wifederg I fl b E. wwwme. SWITCH CONTROLLING MECHANISM.

APPLICATION FILED IUNEZQ. 191B.

Patented Mar. 12, 1918.

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Fdu/ard "(Hen-1667p MGM UNITED STATES PATENT OFFICE.

EDWARDWILLIAM HEDBERG, OF CHICAGO, ILLINOIS.

SWITCH-CONTROLLING MECHANISM.

Application filed June 29, 1916.

To all whom it may concern:

Be 1t known that I EDWARD IV. Hnnnsne,

a citizen of the UnitedStates, residing at Chicago, in the county of Cookand State of lllinois, have invented certain new and useful Improvements in Switch-Controlling lVIec-hanisms of which the following is a specification.

This invention relates to automatic limit switches or the like. I have herein shown my invention applied to a hotwater heating system, but it will'be apparent from the following description and drawings that the invention may be otherwise applied with but slight modifications.

One object of my invention is to provide improved limit switch means which is operable automatically and wherein the limits are adjustable.

IVith'the foregoing and other objects in view the invention consists of the novel combination and arrangement of parts illustrated in the accompanying drawings hereinafter more specifically described and particularly pointed out in the claims.

In the drawings I have shown in Figure 1. a diagrammatic elevational View of "a hot water system' to -which myinvention has been applied. Fig. 2 is an enlarged front elevation of the limit switch shown in Fig. 1. Fig.3 is an enlarged cross section taken on line 33 of Fig. 2 of the limit switch shownthere-and the operating mechanism therefor-shown in Fig. 1. Fig. l is a rear elevational view along the line i-at of Fig. 3. Figs. 5, 6,7 and 8 are enlarged sectional views of the limit switch taken on lines 55, 6-6, 7-7 and 88 of Fig. 2. Fig. 9 is a sectional view taken on line 9-9 of Fig; 3.

In Fig. 1 is shown a diagrammatic view of a hot water heating system comprising a boiler 1 with a check 2 and a draft 3. The usual expansion chamber a is connected to the boiler by any convenient means as the pipe 5. To the chamber 4 is attached an auxiliary chamber 6 containing the operating mechanism for the limit switch 7'. The operating mechanism may, however, if preferred be installed directly in the expansion tank. The switch 7 is connected by suitable wires 8 to the motor means indi cated at 9. The chains 10 are connected to the check 2 and the draft 8 and are operable by the motor means in a manner to be hereinafter more specifically described.

Specification of Letters Patent.

Patented Mar. 12, 1918.

Serial No. 108,569.

The limit switch 7 for controlling the motor circuit comprises a U-shaped block'of insulating material with two side members 11 and 12 spaced apart and connected at the top by a crossbar 13. The block is supported by the brackets I l: which are attached to the auxiliary tank 6. Each of said members l1 and is slotted at 15 and 16, re spectirely, and is adapted to receive stop members comprising contact stud 17 cara plate 18 or 18 and a nut 19, said stop members being adjustable in said slots. Each of said members 11 and 12 carries a eonductostrap 20 slotted similarly to the members so that said slots register with the slots in the members when the switch is as sembled. Ierein I have shown the conductcr strap sunk flush with the insulated member and extending but a portion of the length of that member.

The space between the members 11 and 2 is provided with two conductor guides 21 which are electrically connected to a third conductor strap 2 which is best shown in Figs. 3 and l. A bar 23 near its upper end freely passes through the cross-bar 13 and at its lower end carries a contact plate 2i and a spring clip provided with shoes This spring clip 25 is adapted to slide up and down the block upon the surface of the members opposite to which the 001 ductor straps are attached and in so doing encounters the contact plates 18 andlS which have been placed at I the desired points. The shoe d es not contact the plates while intermediate these positions and the motor circuit will remain open.

At the lower end of the U-shaped block are located the terminals 27 of the switch 7 These comprise the usual contact pins and knurled nuts for connecting the wires 8, 8 and 8 to the straps 20 and 22. To the upper end of the switch the operating mechanism is attached in the following manner. The bar 23 is rigidly connected to a crossbar 28 which in turn is similarly connected to a rod 29. The rod 29 extends downwardly and freely through the cover of the auxiliary tank 6 and is connected to a movable float member 30 which follows the water level in the expansion chamber i, the auxiliary tank being connected to and communicating with the expansion chamber in any suitable manner. The float member may however, be installed in the expansion chamber if desired without departing from the scope of the invention. It is seen that as the float 30 rises and falls, following the rise and fall of the water level in the expansion tank, the slidable contact clip 25 will rise and fall with it and will close the switch when the water has reached the highest desirable level or when it has reached the lowest desirable level. In this manner the motor will be actuated to check the fire or to increase the fire respectively and this switch will remain closed as long as either condition above mentioned exists.

The complete cycle of operation of the various parts is as follows: Assume that a high fire has raised the temperature of the water and the level of the water in the expansion tank has been raised correspondingly. This raises the float which in turn raises the slidable switch element until the upper limit of travel is reached as indicated by the position of the upper switch contact 18. As long as the level of the water remains or exceeds the level at which the float has closed this switch, the switch will continue to remain closed. ,losing this switch completes the motor circuit which will remain closed until the motor has rotated sufficiently whereupon the branch of the motor circuit through plate 18 will be opened at the motor by suitable means not shown and the other branch through plate 18 will be closed at the motor and will remain so until the clip 26 contacts plate 18 and the motor is again actuated.

It is obvious that various changes may be made in the embodiment herein illustrated without departing from the spirit and scope of the invention, and while I have described in some detail a specific embodiment of my invention which I deem to be new and advantageous, I do not desire to be understOOd as limiting myself in respect to the broader features of my invention except as stated in the appended claims.

I claim as my invention;

1. A limit switch having, in combination, a U-shaped insulating body comprising two side members spaced apart and having two parallel slots, limit stops adjustable in the slots of said members, operating terminals adapted to be connected to said stops, a movable member connected to an additional terminal and adapted to slide in the space between said side members and to be in contact with but one of said stops at the same instant for closing a circuit through the switch, and means for sliding said movable member.

2. A limit switch having, in combination an insulating body portion having conducting straps thereon, limit stops connected to two of said straps, a conducting guide connected to a third strap and a movable contact member slidablc on said guide and having a pair of arms each adapted to contact one of said stops for closing different circuits through the limit switch.

3. A limit switch including an insulating body having two spaced parallel slots, a conducting stop adjustable in each slot, a conducting strap for each of said stops adjacent said slots, a conducting guide located between said slots, an operating terminal connected to each of said conducting straps and said guide, a conducting member slidable in said guide and having a contacting arm for each stop, and means for moving said member, each stop being arranged to be engaged by its arm in the movement of the member to complete a circuit with its conducting strap and the guide.

In testimony whereof I have hereunto set my hand.

EDWARD WILLIAM HEDBERG.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. 0." 

